<div class="card">
    <div class="card-header">
        教室：{{classroomName}}
    </div>
    <div style="display: flex;flex-direction: row;">
        <client-list ref="client_list"></client-list>
        <video style="display: block;width: 480px;height: 320px" autoplay ref="remote_preview"></video>
    </div>
</div>